import math
import re
from random import choice


def jia(num1, num2):
    return num1 + num2
def jian(num1, num2):
    return num1 - num2
def cheng(num1, num2):
    return num1 * num2
def chu(num1, num2):
    if num2 == 0:
        print("除数不能为0")
        return 0
    return num1 / num2
def miyunsuan(num1,num2):
    return math.pow(num1,num2)
def mod(num1,num2):
    return num1 % num2

def analy_expression(expression):
    pattern = r'(\d+)([+\-*/]|mod)(\d+)='
    match = re.match(pattern, expression)
    if match:
        num1 = match.group(1)
        cho = match.group(2)
        num2 = match.group(3)
        return {
            'num1': int(num1),
            'num2': int(num2),
            'cho': cho
        }
    else:
        raise ValueError("输入的算式格式不正确")

expression="000"
while(expression!="q"):
    expression=input("请输入算式（eg：9*8=），输入q退出:\n")
    if(expression!="q"):
        result1 = analy_expression(expression)
        num1=result1['num1']
        num2=result1['num2']
        choice=result1['cho']
        if choice == "+":
            print(num1, choice, num2, " = ", jia(num1, num2))
        elif choice == "-":
            print(num1, choice, num2, " = ", jian(num1, num2))
        elif choice == "*":
            print(num1, choice, num2, " = ", cheng(num1, num2))
        elif choice == "/":
            print(num1, choice, num2, " = ", chu(num1, num2))
        elif choice == "^":
            print(num1, "^", num2, "次方 = ", miyunsuan(num1, num2))
        elif choice == "mod":
            print(num1, "mod", num2, "=", mod(num1, num2))